import wx
class Application(wx.Frame):
    def __init__(self, parent):
        wx.Frame.__init__(self, parent, -1, 'My GUI', size=(400, 300))
        panel = wx.Panel(self)
        sizer = wx.BoxSizer(wx.VERTICAL)
        panel.SetSizer(sizer)
        txt = wx.StaticText(panel, -1, 'Hello World!')
        sizer.Add(txt, 0, wx.TOP|wx.LEFT, 20)
        self.Centre()
        self.Show(True)
app = wx.App(0)
Application(None)
app.MainLoop()
